mysql - Update C# client whenever database is updated

Question

I am using MySQL with C# / Visual Studio 2008. I need to know any method so that if one user updates the database, all the logged in users over the network, are notified that a change has been occurred. If i logged in the database through my application, at that time the serial no of the latest record in the database was 10, and then i someone with the privileges updates the record in the database and at the same time i am being notified that the database has been updated with a new record. Common example can be of MSN messenger's alert for a friend when he gets online... Though i really don't want that popup, but alert functionality is something like that...

One more thing to ask: I want a functionality like if a record's status is not updated (for say about more than 3 hours), then i want all users to get alert about that issue also. This functionality is needed for all of the records, not specifically for new records.

Answer 1

Quite a long answer, but your best bet would be something like SqlCacheDependency.

Also you could use something called the "Reverse AJAX" technique, which is used by Google Mail notifications, and talked about here: How does incoming mail notification on Gmail works?

Besides those two, your own other options AFAIK is simple server polling.

Also, you haven't mentioned what your client is.

Is it a public web site on the internet? Is it an intranet app, it is a WPF app?

If it's a web site, you're best best is client-side callbacks using the Reverse AJAX technique i mentioned.